The present invention relates to methods and apparatus for inserting an elastic member in the transverse direction of a product, and more specifically to methods and apparatus for placing elastic members in the waist-encircling portion of a disposable diaper.
Over the years, there have been a number of products which have an elastic member disposed in the transverse direction of the product, such as plastic pants, training pants, and the like. The elastic members may be sewn or adhered to the product in various manners as are well known in the art. Recently, there have come on the market a number of disposable diapers, which have elastic members inserted in the longitudinal direction of the product to make the leg-encircling portion of the diaper elastic. There are also a number of U.S. Patents which describe such products and methods for their manufacture such as U.S. Pat. Nos. 3,860,003; 4,050,462, and 4,081,301.
There are a number of U.S. Patents which describe elastic means disposed in the waist-encircling portion of a diaper or other techniques for providing stretch in the waist of the diaper or similar product; for example, see U.S. Pat. Nos. 3,920,018; 3,951,150; 3,990,450; 3,995,638; 4,036,233 and 4,041,949. To the best of my knowledge, none of the products having elastic waistband areas as described in these patents has enjoyed any commercial success. It is believed a primary reason for this lack of success is that no efficient, economical method has been discovered for inserting the elastic member in a suitable position in a diaper so as to render the waist-encircling portion of the diaper stretchable.
What I have discovered is a simple, economical, efficient, fast method for inserting elastic members transverse of a continuous web.